<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        #idStyle {
            font-size: 50px;
        }
        
        .classStyle {
            font-size: 30px;
        }
        
        a {
            color: skyblue;
        }
        
        a :hover {
            color: red;
        }
        
        .classStyle heightStyle {
            height: 50px;
        }
        
        #idStyle widthStyle {
            width: 30px;
        }
        
        .classStyle .sonClassStyle {
            color: sans-serif;
            -color: brown;
            border: 1px solid black;
        }
        
        #idStyle #sonIdStyle {
            color: aqua;
            border: 1px solid pink;
        }
    </style>
</head>

<body>
    <form action="https://www.baidu.com/s?">
        <div>
            <input type="text" name="word">
            <button type="submit">度百搜索</button>
        </div>
    </form>
</body>

</html>